(P 435) A PHASE II STUDY OF HIGH DOSE IFOSFAMIDE IN METASTATIC/LOCALLY ADVANCED SYNOVIAL SARCOMA FROM A TERTIARY CARE CENTER IN INDIA

Objective: There have been no prospective trials examining single agent ifosfamide at 11g/m2 specifically in synovial sarcomas. In the relapsed setting, the treatment options are limited and it is important to maximize use of existing regimens. Being a chemosensitive disease, it is important to evaluate this chemotherapy regimen in a prospective study with diagnosis of synovial sarcoma confirmed by FISH. Others treatment options like Anlotinib and cellular therapies like afamitresgene autoleucel are either expensive or not suitable due to very low positivity of HLA-02 in Indian population
As Indian and international data is lacking, we are doing this phase II study and analyse the effectiveness of this drug in this particular sarcoma type.
Primary objective:
• To study single agent ifosfamide in relapsed metastatic synovial sarcoma patients as determined by overall response rate (Complete response + Partial Response)
Secondary objectives include overall survival, Toxity profiles, Quality of life analysis and median progression free survival

Methods: Study design: Single arm, Phase II, Simon 2-stage clinical trial
Study setting:
The study will be conducted at Department of Medical Oncology, BRAIRCH, AIIMS, New Delhi. After screening and registering the patients who meet the inclusion criteria, the patients will be enrolled into the trial. Oncology nursing staff under supervision of medical oncologist will provide the chemotherapy.
Treatment administered
Inj Ifosfamide 11g/m2 given over 4 days q 21 days for 4 cycles
Inj MESNA 3g/m2 d1- d4
G-csf support for 5 days from d5 –d9/ peg-gcsf on D3

Radiological response assessment would be done using RECIST v1.1 after 4 cycles

Patients having objective response will recieve 2 more cycles as mentioned above and will have final response assessment post cycle 6
Patients will be kept under regular interval followup after treatment completion.

This trial is registered under clinical trials registry of India CTRI/2024/03/063743 on 6th march 2024

Simon minimax two stage, one-sample, testing procedure is applied. Sample size of 25 is calculated

The trial is currently in stage 2 after showing favourable reponse in stage 1 and accuring patients
at the time of this abstarct submission 21 patients have been recruited and response assessments have been done for 15 patients who completed atleast 4 cycles of chemotherapy showed objective response rate in 10 patients ( 66.6% response rate) final analysis will likely be completed in next 2 months

Results: N/A

Conclusion: N/A